Use Homebrew's gitconfig for various commands

Git is a transport and storage mechanism for us so we don't want to
allow arbitrary customisation of this due to user issues e.g. #3664
and #3561.

Fixes #3664.

3 files changed, 7 insertions, 1 deletions

diff --git a/Library/Homebrew/cmd/log.rb b/Library/Homebrew/cmd/log.rb
index 898e921ba..64e8a2e64 100644
--- a/Library/Homebrew/cmd/log.rb
+++ b/Library/Homebrew/cmd/log.rb
@@ -39,6 +39,6 @@ module Homebrew
     end
     args = ARGV.options_only
     args += ["--follow", "--", path] unless path.nil?
-    exec "git", "log", *args
+    Utils.with_homebrew_gitconfig { exec "git", "log", *args }
   end
 end
diff --git a/Library/Homebrew/cmd/update-reset.sh b/Library/Homebrew/cmd/update-reset.sh
index 5ba8ec9d8..3b166b8ed 100644
--- a/Library/Homebrew/cmd/update-reset.sh
+++ b/Library/Homebrew/cmd/update-reset.sh
@@ -28,6 +28,8 @@ EOS
     set -x
   fi
 
+  export HOME="$HOMEBREW_LIBRARY/Homebrew/gitconfig"
+
   for DIR in "$HOMEBREW_REPOSITORY" "$HOMEBREW_LIBRARY"/Taps/*/*
   do
     [[ -d "$DIR/.git" ]] || continue
diff --git a/Library/Homebrew/cmd/update.sh b/Library/Homebrew/cmd/update.sh
index 747784527..c28a79d02 100644
--- a/Library/Homebrew/cmd/update.sh
+++ b/Library/Homebrew/cmd/update.sh
@@ -19,7 +19,11 @@ git() {
   then
     GIT_EXECUTABLE="$("$HOMEBREW_LIBRARY/Homebrew/shims/scm/git" --homebrew=print-path)"
   fi
+  OLDHOME="$HOME"
+  export HOME="$HOMEBREW_LIBRARY/Homebrew/gitconfig"
   "$GIT_EXECUTABLE" "$@"
+  export HOME="$OLDHOME"
+  unset OLDHOME
 }
 
 git_init_if_necessary() {